Housings for elastic fluid turbines



Feb. 16, 1960 H. T. LUSCH 2,925,249

HOUSINGS FOR ELASTIC FLUID TURBINES Filed June 5, 1957 United States Patent HOUSINGS FOR ELASTIC FLUID TURBINES Herbert Theodor Liisch, Finspong, Sweden Application June 5, 1957, Serial No. 663,814

Claims priority, application Sweden October 2, 1956 1 Claim. (Cl. 253-39) The present invention relates to housings for elastic fluid turbines and more particularly to turbine housings of the type which comprises an inner annular casing for receiving the driving fluid and an outer annular casing concentricallysurrounding said inner casing in spaced relation thereto sothat there will be a space for cooling air between the two casings. 7

According to a feature of the invention the inner casing is provided with conical walls slidablymounted in the correspondingly conical walls of the outer casing concentrically surrounding the inner casing, all of said conical walls having substantially the same apex.

The accompanying drawing shows an axial section of a housing according to the invention and portions of the respective turbine rotor.

With reference to the drawing, hot gas under pressure is supplied from a source, such as a combustion chamber or chambers, not shown, through a pipe or pipes 1 to the turbine rotor 2, via the turbine housing. The turbine housing comprises an inner annular casing 3 and an outer, likewise annular casing 4 concentrically surrounding said inner casing in spaced relation thereto. The space 5 left between the two casings is adapted to be traversed by a cooling medium, as air of approximately the same pressure as that of the gas traversing the casing 3. By this expedient the inner casing 3 may be relieved of the gas pressure but, will still be subjected to the very high temperature of the gas passing through the inner casing while the external surface of the inner casing is cooled by the cooling medium passing through between the casings 3 and 4. The outer casing 4 on the contrary has to withstand the whole pressure of the cooling medium but is kept comparatively cool under the influence of said medium.

Considering their dilferent purposes the two casings or shells should be made of different materials so as to get different temperature expansion coeficients. In addition, the materials may have very different and varying temperatures while in operation. It is thus seen that the two casings will expand in different degrees with respect to each other. It is therefore highly desired to so mount the inner casing within the outer casing as to allow it to expand freely with relation to the outer casing at all temperatures and any variation of temperature while being still guided by the outer casing. This result may be achieved by the present invention.

Patented Feb. 16, 1960 To this end the casings are arranged concentrically with relation to the axis of the turbine, the inner casing 3 being mounted within the outer casing 4 by means of ledges 6 secured to any of the casings: along which the casings may slide with relation to each other due to expansions and contractions. The sliding surfaces are located along imagined conical surfaces having a common apex at 7. By this arrangement all sliding surfaces will act positively upon a change of dimensions of any casing with relation to the other, that is to say, the inner casing remains guided by the outer casing both radially and axially.

In order that conical casings having a small angle of cone may not be liable to get jammed to each other the walls of the inner casing 3 are formed on their axially extending inner end portions with annular flanges 8 radially projecting therefrom in a plane at right angles to the axis of the turbine which plane extends through the apex 7. Said flanges engage correspondingly located annular grooves formed in the inner surfaces of the walls of the outer casing 4. By this means an additional locking of the casings to each other is achieved. The radial expansion may take place freely owing to the provision of radial plays between the flanges 8 and said grooves, as shown at 9.

It is to be noted that also the axes of the inlet pipes 1 l are pointing towards the apex 7 and that said pipes are mounted so as to be capable of sliding longitudinally with relation to the casing 3. By this means said pipes may displace themselves telescopically with relation to casing 3.

I claim:

In housing for an elastic fluid turbine in combination, an inner annular casing concentrically surrounding the turbine axis for receiving and passing the driving fluid to the turbine, an outer annular casing concentrically enclosing said inner casing in spaced relation thereto for constituting a cooling jacket therearound, both of said casings having conical inner and outer circumferential walls all tapering substantially towards a common apex situated on the axis of the turbine with the walls of the inner casing slidably mounted in those of the outer casing, means on said casings forming a flange engagement therebetween in a plane extending through said apex substantially at right angles to the axis of the turbine for locking the casings against axial movement with relation to each other while allowing relative radial movements therebe tween, pipes for suplying driving fluid to the inner casing connected to the rear end thereof so as to be capable of sliding longitudinally with relation thereto in directions pointing towards the common apex of the conical circumferential walls of the casings.

References Cited in the file of this patent UNITED STATES PATENTS 2,710,503 Boyd June 14, 1955 2,775,470 Bixler et a1. Dec. 25, 1956 2,793,832 Wheatley et al. May 28, 1957 

